Relay: update setup code, rework masking

[mcspr]

• add u32{to,from}String that use strtoul instead of itoa, add 0b 0o 0x prefix checks
• update boot mask to use kv storage instead of raw eeprom byte, add migration code
• update boot mask only after relay status really changes
• move relay prototypes.h entry into the relay.h, update .ino files to reference it
• move relay header defaults (RELAY1_PIN etc.) to the relay_config.h
• refactor c struct into a simple c++ struct, add default and minimal pin+type+reset_pin based on id constructors, thus removing the need to push_back into the array.
• fix DUMMY_RELAY_COUNT=0, use default constructor via _relays.resize(DUMMY_RELAY_COUNT + _relays.size)

[mcspr]

wrong issue the first time...

Skipping configuration 'EEPROM_RELAY_STATUS' since the value of 'EEPROM_RELAY_STATUS' is unknown. Use -D if you want to check it. You can use -U to skip it explicitly.

uint8_t mask = EEPROMr.read(EEPROM_RELAY_STATUS);

Skipping configuration 'EEPROM_RELAY_STATUS' since the value of 'EEPROM_RELAY_STATUS' is unknown. Use -D if you want to check it. You can use -U to skip it explicitly.

EEPROMr.write(EEPROM_RELAY_STATUS, 0xff);

Codacy / cppcheck false positive. Something about the headers :/